Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Trachyandesite is an extrusive igneous rock.
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Quench
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture
Commercial Uses
Creating Artwork, Gemstone
Creating Artwork, Pottery
Types
Cataclastic rock
Basaltic Trachyandesite
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Trachyandesite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
Light to dark brown
Light to dark brown
Porosity
Less Porous
Less Porous
Specific Gravity
2.46-2.86
2.8-3
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
India, Russia
Africa
Western Africa
South Africa
Europe
Great Britain, Switzerland
Iceland
Deposits in Western Continents
North America
-
Canada, USA
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-
Pseudotachylite vs Trachyandesite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Pseudotachylite vs Trachyandesite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Trachyandesite. Learn more about Pseudotachylite vs Trachyandesite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Trachyandesite include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Pseudotachylite and Trachyandesite, they have various applications in construction industry. The uses of Pseudotachylite in construction industry include As dimension stone, Cement manufacture, For road aggregate, Making natural cement and that of Trachyandesite include Building houses or walls, Cobblestones, For road aggregate, Rail track ballast, Roadstone.
More about Pseudotachylite and Trachyandesite
Here you can know more about Pseudotachylite and Trachyandesite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Trachyandesite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Trachyandesite includes Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Trachyandesite, the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas, Trachyandesite is available in black, brown, light to dark grey colors. Appearance of Pseudotachylite is Dull and Soft and that of Trachyandesite is Dull and Soft. Properties of rock is another aspect for Pseudotachylite vs Trachyandesite. The hardness of Pseudotachylite is 7 and that of Trachyandesite is 4-5. The types of Pseudotachylite are Cataclastic rock whereas types of Trachyandesite are Basaltic Trachyandesite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pseudotachylite and Trachyandesite is light to dark brown. The specific heat capacity of Pseudotachylite is 0.92 kJ/Kg K and that of Trachyandesite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Pseudotachylite is heat resistant whereas Trachyandesite is heat resistant, pressure resistant, wear resistant.